I picked up a used Sigma EF-530 DG iTTL flash to serve as a backup to my SB-700. I was hoping I could use the D7000's pop-up flash in Commander mode to trigger both the SB-700 and the EF-530 off camera. The SB-700 supports wireless iTTL functions which is way cool. I can change flash compensation on the camera body and the SB-700 gets the signal. The EF-530 is basically an optical slave unit- power settings must be set on the flash itself no matter what you have dialed in on the camera.

Here's my setup for testing. The SB-700 is on the left (on the stand). EF-530 is on the right (on silver canister). Interestingly, the little P&S camera used for this pic actually fired the EF-530. Good to know if there is someone else firing off a flash nearby.

I can get each flash to fire individually just fine. See pics below.

Camera left SB-700 1/16 power (set in menu e3 on D7K)

Camera right EF-530 1/16 power

Here's my problem:

1) When both flashes are in Remote/Slave mode, only the EF-530 will fire. If I block the flash from the EF-530, the SB-700 will fire OK so it's definitely the flash from the EF-530 that's screwing with the SB-700. Is there a way to get both flashes to fire using the pop-up flash on the D7K?

2) The EF-530 will only fire at 1/2 power or lower. It will not fire if it's set to 1/1 power. Not sure what's going on here?